ECJ EUROPEAN Cleaning Journal

Concerns about Hospital Acquired Infections (HAIs) have certainly highlighted the need to prevent the spread of germs in healthcare settings. However a new US report reveals a disturbing gaps in knowledge when it comes to the most effective ways of cleaning surfaces.

Tray tables, bed rails, light switches, toilets - all of these are common surfaces for swapping germs between patients and healthcare workers. But what is the most effective way of cleaning them? According to a new systematic overview published in the Annals of Internal Medicine in the US there is a lack of evidence as to which method of cleaning high-touch surfaces is the best.

The systematic overview was led by Craig Umscheid MD, Jennifer Han MD, Brian Leas MS and Nancy Sullivan at the University of Pennsylvania School of Medicine. They examined 80 studies published between 1998 and 2014 and found that comparative effectiveness studies were uncommon. Such studies would have directly compared different ways of cleaning, disinfecting, and monitoring the cleanliness of hard surfaces in order to determine which were most effective.

There were also relatively few studies that focused on measuring outcomes of most interest to patients, such as changes in HAI rates or the presence of pathogens on patients. Only five of the studies were randomized controlled trials.

Instead, the existing studies were largely before and after experiments, comparing the magnitude of surface contamination after cleaning with a particular agent to the magnitude of contamination before cleaning. Over 65 per cent of the studies assessed surface contamination, such as bacterial burden and colony counts, as the primary outcome. Less than 35 per cent reported on patient-centred outcomes such as HAI rates or acquisition of a specific organism in the body, known as colonisation.

"The cleaning of hard surfaces in hospital rooms is critical for reducing healthcare-associated infections," said Han, the study's lead author. "We found that the research to date does provide a good overall picture of the before and after results of particular cleaning agents and approaches to monitoring cleanliness. Researchers now need to take the next step and compare the various ways of cleaning these surfaces and monitoring their cleanliness in order to determine which are the most effective in driving down the rate of hospital-acquired infections."

While studies examining HAIs have increased over the last 15 years, infections acquired in the hospital remain a leading cause of death and morbidity. In 2011, there were over 721,000 HAIs in the US, according to the most recently available data from the US Centers for Disease Control and Prevention (CDC). And many experts believe only 50 per cent of surfaces are typically disinfected during cleaning of a patient's room.

The team looked at three broad categories of evidence:
• Which agents and methods were used to clean hard surfaces
• What approaches were available to monitor the effectiveness of cleaning
• What systems-level factors are needed for cleaning and monitoring to be successful.
In addition to its literature review, the researchers interviewed a number of national experts.

"Our goal was to provide a comprehensive review of evidence in all three domains," said Umscheid, the study's senior author. "While there is a clear need for more patient-centred and comparative effectiveness research, the findings that do exist provide a good place to start in terms of a hospital or health care entity seeking information on ways to mitigate healthcare-associated infections."

Among its findings, the EPC team identified several studies showing that rates of C.difficile, the most common cause of hospital-acquired gastrointestinal infections, fell with the use of bleach-based disinfectants but that a chlorine dioxide-based product was ineffective in reducing C.diff contamination and infection rates. Patients taking antibiotics are at special risk of becoming infected with C.diff because antibiotics can disrupt the normal bacteria of the bowel. According to the CDC, C.diff caused almost half a million infections in the United States in 2011.

In addition, six studies integrating various wipes moistened with hydrogen peroxide and other chemicals into preventive strategies reported positive outcomes, including sustained reductions in HAIs. Seventeen studies implementing ‘no-touch' modalities to clean hard surfaces - such as devices that emit ultraviolet light or hydrogen peroxide vapor - reported positive findings, with three specifically demonstrating reductions in infection rates.

Seven out of eight studies evaluating enhanced coatings on hospital room surfaces, such as copper-coated bed rails, reported positive findings. Surfaces made of solid, copper-based metals or alloys were found to continuously kill bacteria that cause infections.

The EPC team also highlighted several priority areas for future research, based on their review of the evidence and interviews with leading experts. Questions to emphasise in future studies include: what surfaces present the greatest infection risk to patients, what benchmarks should be established for measuring cleanliness, and what factors affect the quality of routine disinfection practices? Further research is also needed on recently emerging disinfection strategies.

"In addition to expanding the use of comparative effectiveness research and placing greater emphasis on patient-centred outcomes, future research should investigate the effectiveness of a number of promising new technologies and approaches," said Han. "These include self-disinfecting coatings and increasingly used surface markers for monitoring the presence of pathogens. Other challenges include identifying high-touch surfaces that confer the greatest risk of pathogen transmission and developing standard thresholds for defining cleanliness."

In an accompanying editorial, Tara Palmore MD and David Henderson MD of the NIH Clinical Center in Maryland, wrote that "the gaps in the evidence base for hospital environmental cleaning and disinfection methods and monitoring will be filled best by randomised, controlled trials rather than quasi-experimental studies."

However ‘quasi-experimental studies' are easier and less costly to do than a large randomised control trial, but they do not show how different cleaning practices compare or how cleaning practices impact patient outcomes, Han noted.

"In addition to lacking a tight web of evidence, we still lack the means to ensure that the environmental cleaning procedures are followed consistently," Palmore and Henderson wrote. "Even in a facility with a strong culture of safety, environmental service workers are sometimes a marginalised part of the healthcare staff and may not always appreciate or be appreciated for the patient safety aspect of their work. Effective communication and education are essential, as are actionable, meaningful outcome measures."